In motor vehicle structures, the side doors of vehicles often deform as the vehicle travels, particularly at higher speeds. For example, in the case of doors that pivot about a hinge pin, the upper rear corner of the window surround tends to move away from the vehicle body while the rear lower corner of the door moves closer to the vehicle body. The faster the vehicle travels, the greater the pressure difference between the interior and the exterior of the vehicle and the more the door deforms. Likewise, larger doors having lower torsional stiffness tend to deform more.
This propensity to deform is also particularly detrimental to the resistance against break-in because it is possible to force the surround away from the door.
The outward displacement of the upper rear corner of the door is particularly detrimental to the sealing of the cabin against air ingress. For example, per 10 millimeters of displacement of the upper rear corner of the front door window surround under a separating force of 20 decanewtons, 7 to 8 millimeters are of a geometric nature and originate from a rotation of the bottom part of the door about an axis running between the lock and the upper door hinge. The rest of the deformation originates from pure bending of the window surround.
To solve this problem, U.S. Pat. No. 6,283,534 discloses a vehicle door with a moving surround. The door comprises a first structure connected such that it can move to the vehicle body of the vehicle and a second structure connected to the first structure such that it can pivot about a roughly horizontal axis. The second structure comprises the window surround. The door also comprises a mechanism to cause the second structure to pivot with respect to the first structure. Thus, when the door is closed, the second structure is pivoted in such a way that the window surround exerts a force on the door seal situated between the vehicle body and the door. The disadvantage of such a solution is that the door has a complex structure and expensive to manufacture.
One possible solution also involves altering the cross section of the door seal between the door and the vehicle body. Overcompressing the seal makes it possible to compensate for some of the deformation and to reduce the noise generated by the wind when the vehicle is traveling at high speed. The disadvantage is that the user has to exert more energy to close the door and has to apply more force to undo the lock in order to open the door.
Another proposed solution includes a fixed rubber stop at the bottom of the door, the door being able to pivot about hinges. When the door is closed, the stop comes into contact with the chassis of the vehicle and opposes the rotation of the bottom part of the door at high speed so as to force the window surround against the vehicle body. The disadvantage here again is that the user has to slam the door harder to close it in order to overcome the forces due to the presence of the stop. Furthermore, the lock is overengineered in order to overcome the additional forces due to the seals and/or to the rubber stop, these elements having a tendency to push the door outwards.
There is therefore a need for a vehicle that solves the problems generated by the deformation of the doors while at the same time making sure that the door is easy to open and close.